Add files for basic Sphinx documentation
Add docs _build directory to gitignore file
Add usage file with Quickstart documentation
Include CHANGES file in documentation
Test building documentation with tox
Improve formatting of tox file
Remove South from tests
Add more tox tests and fix envlist formatting
Use coveragerc file for coverage reporting
Link to documentation in README file
Add querying information to usage documentation
Document tracking history on third-party apps
Add documentation for usage with South
Add documentation for ``_history_user`` property